This invention relates to a draw spring linkage, particularly a tail wheel draw spring linkage for a light aircraft.
A conventional light aircraft has a vertical stabilizer and a rudder that is attached to the vertical stabilizer and is pivotable relative to the vertical stabilizer about an approximately vertical axis. Rudder control cables are connected to a rudder control horn (a generally horizontal bar that is attached to the rudder at its lower end and extends to each side of the rudder) to allow the pilot to adjust the angular position of the rudder in flight.
Light aircraft with conventional landing gear are commonly equipped with spring-loaded tail wheel steering linkages that connect the rudder control horn to the tail wheel for positive steering control while on the ground. Typically, the tail wheel is mounted for pivotal movement about an axis that is approximately parallel to the pivotal axis of the rudder and is coupled to a tail wheel horn (a generally horizontal bar that is attached to the tail wheel and extends to each side of the tail wheel). The traditional tail wheel steering linkages comprise draw springs that are connected between the control horns of the rudder and the tail wheel. The draw springs provide shock absorption to protect the rudder control system in the event that the wheel strikes an irregularity during taxiing, take-off or landing. The draw spring linkage is constructed so that the two ends of the linkage remain connected even if the spring fails. The draw spring that is used in the traditional tail wheel steering linkage has some disadvantages, including the fact that it is bulky and not aerodynamic, it is prone to corrosion, and the clips that attach the linkage to the tail wheel control horn may open up and detach in use unless they are wired closed.